Transcript Effects on Indoor Air Quality of Outgassing of Household

Effects on Indoor Air Quality of
Outgassing of Household Materials
Or
How The Things Your House Is
Made of Are Trying to Slowly Kill
You
Michael Mckenzie
Indoor Air Quality
• Most people familiar with common pollutants
such as dust, CO, methane (natural gas leaks),
asbestos, etc.
• Others are at least aware of other less
prominent problems: O3 from machines,
radon, cleaning supplies, cooking fumes
• Almost no thought given to solid objects
What Solid Objects Should I be Scared Of?
• Furniture, Upholstery, Plywood, Particle
Board, Faux Wood Laminates, Dried Adhesives
and Paints, Carpets, Cosmetics, Foam
Insulation, Glass Fiber Insulation, Faux
Leather, Plastic Toys, Plastic Kitchen Ware,
Stucco, Concrete, Bricks, Dyed Fabric, Window
Frames, Synthetic Windows, Rubbers,
Waxes…..Need I say More?
What Comes Out of Them?
• VOC’s: Toluene, Benzene, Naphthalene,
Formaldehyde
• Plasticizers: (phthalates)- used in plastics for softness
and flexibility
• Organochlorines: found in plastics and electronics,
(tink PVC and PCB)
• Particles: Dust, fibers, toxic metals, etc
• These chemicals responsible for familiar smells, (“new
car smell,” “clean house smell,” etc)
• Many of these cause chronic illness and are
carcinogenic
Sick Building Syndrome
• Buildings that make inhabitants
feel “icky” to dysfunctional
• Caused by poor lighting, poor
ventilation, presence of various
pollutants, including those
outgassed by common objects
and construction materials
• Big problem for older offices and
housing
Multiple Chemical Sensitivity
• Describes people with severe symptoms triggered
by exposure to chemicals
• Symptoms can range from general nausea,
headache, and fatigue, to flu-like sickness, to
severe dysfunction of entire body, (Jean
Enwright).
• Exact details controversial in medical community;
opposing theories include psychological issues
and pre-existing sensitivities/ allergies
Focus on Formaldehyde
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Good representative of outgassed chemicals due to prevalence in so many
products, (widely known as embalming fluid).
Background outdoor concentration: 0.01-0.03ppm from combustion
Can smell it at ~0.1ppm This is a standard indoor air safety limit
Homes and workplaces often register 1-3ppm in bad cases
Outgassing increased with temperature and humidity
Acts as strong irritant; can cause headaches, dizziness, breathing problems; in the
long term, can affect nervous system and is a likely carcinogen
Already banned in one type of insulation, but still allowed in smaller amounts in
many products.
Case Study: Occupational Exposure in Plywood/ Particle Board
Manufacture
The average personal exposure was to 1.13ppm of formaldehyde. Exposure
to formaldehyde was associated with… several respiratory symptoms and
diseases, including cough, phlegm, asthma, chronic bronchitis, and chest
colds. The results of the study support the hypothesis that chronic
exposure to formaldehyde induces symptoms and signs of chronic
obstructive lung disease.
Simple Box Model: Formaldehyde Exposure In a
3 person Home
• Assumptions:
– Walls and flooring made from formaldehyde-outgassing materials, (particle board,
plywood, synthetic carpets); overestimate accounts for other sources in home not
included
– Model home as single room; 1000 sq ft with 8ft ceiling.
– Air changes per hour vary from 0-3
– Based on published study, materials ougas at rate of 1-20 mg/m^2/day
– Assume materials freshly installed, constant emissions, steady state
• Governing Equation:
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E=emission rate
As=Source surface area
Q=Flowrate
V=House air volume
𝑉
𝑑𝑐
𝑑𝑡
= 𝑄𝑖𝑛 𝐶𝑖𝑛 − 𝑄𝑜𝑢𝑡 𝐶𝑜𝑢𝑡 + 𝐸𝐴𝑠 -loss
Model Results
To achieve safe levels, with high outgassing, need to increase ventilation
X2-5 times largest average residential systems.
House Full Of 20 Plants
What To Do Now
• Important to understand the wide array of potential
health impacts common items can have
• Even if you aren’t noticeably chemically sensitive, why
take risks?
– Make sure indoor environments are well ventilated at
minimum.
– Consider swapping outgassing materials for more stable/
natural ones.
– Give potentially harmful products time to outgass before
bringing them into your home/ office, (anywhere from
several days to weeks).
– Buy housplants known to filter out VOC’s
• Boston fern, pot mum, date palm, etc.
References
(In Case You Don’t Believe Me)
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Rousseau, David. Your Home, Your Health and Well Being. Ten Speed Press. 1988
Dunford, Randall Earl. Your Health & the Indoor Environment, 2nd ed. NuDawn Pub.
1994
Tan Malaka M.D., Dr. P.H. & Arthur M. Kodama Ph.D. (1990): Respiratory Health of
Plywood Workers Occupationally Exposed to Formaldehyde, Archives of
Environmental Health: An International Journal, 45:5, 288-294
USA Consumer Product Safety Commission. An Update on Formaldehyde.
Publication 725. 2013 Revision.
Rogozen, Michael B. et al. Formaldehyde: A Survey of Airborne Concentrations and
Sources. Prepared for State of California Air Resources Board by Science
Applications, Inc. 25 June 1984.
Baumann, Melissa G.D. et al. Terpene Emissions From Particleboard and MediumDensity Fiberboard Products. Composites and Manufactured Products. Forest
Products Journal. Vol 49. No1. January 1999.
Wolverton, B.C., Wolverton, John D. Plants and Soil Microorganisms: Removal of
Formaldehyde, Xylene, and Ammonia From the Indoor Environment. Wolverton
Environmental Services. Journal of the Mississippi Academy of Sciences. Vol 38, No
2. August/ September, 1993.